Process for manufacturing aryl-ortho-carboxyamido-mercaptans



Patented Sept. 13, 1932 TES PTENT OFFICE RICHARD HERZ, OF FRANKFORT-ON-TI-IE-MAIN, AND MAX SCHUBERT, OF FRANKFORT- ON-THE-MAIN-FECHENHEIM, GERMANY, ASSIGNORS TO GENERAL AN ILINE WORKS, INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE PROCESS FOR MANUFACTURING ARYIi-OR'lI-IO--('JARBOXYAIVIIDO-1V[ERCAZETANSv N Drawing. Application filed January 29, 1929, Serial No. 336,005, and in Germany January 31, 1928.

We have found that ortho-cyanogen-arylsulfocyanogen compounds of the general formula one a! y somz O ONHzO) a W SH(2) are obtained in a smooth reaction. They are capable of being condensed with monochloro-acetic acid in an alkaline solution to form the corresponding aryl-carboxyamidoortho-thioglycollic acids.

The ortho-cyanogen-aryl-sulfocyanogen compounds are advantageously at first dissolved or suspended for instance in sulfuric acid of about 90% strength, the mixture is allowed to stand in the cold for some hours and the reaction products are isolated by pouring the mixture into water. For the further treatment on a technical scale the aryl-carboxy-amido-ortho-mercaptans need not be isolated, but the mercapto products t may be directly, after having been treated with an alkali, condensed in the customary manner in the alkaline solution with monochloro-acetic acid.

The aryl-ortho-carboxy amido mercaptans are important intermediates for manufacturing thioindigo dyestuffs.

In order to further illustrate our invention, the following examples are given, the parts being by weight and all temperatures in Centigrade degrees. We wish it however to be understood that we are not limited to the particular products nor reaction condi- 5o tions mentioned therein.

Example A solution of 10' parts of Lmethyl-Q-cyanogen-3-sulfocyanogen-5-chloro-benzene in i5 100 parts of sulfuric acid of 90% strength is stirred at room temperature (2025) for some hours. Then the mass is poured into 1000-2000 parts of cold water and the reaction product separated in the form of yellow flakes is filtered ofi. It represents when recrystallized from spirit colorless, needles melting at 182183. According to the anallysis it corresponds probably to the formu a: s l

CONE:

Cl SOONH! Ewample 2 A solution of 8 parts of l-cyanogen-Q-sulfocyanogen-L-chloro-benzene in 100 parts of sulfuric acid of strength is stirred at a room temperature (QC-25) for about 20 hours. Thereby a pulp of fine needles is formed which is filtered and freed from acid by washing. Then dry the reaction prodnot thus obtained melts at about 305. According to the analysis and its chemical behaviour it corresponds probably to the formula:

OONHQ CI- S H In order to prepare the corresponding thioglycollic acid the mercaptocompound is 1 condensed with monochloro acetic acid.

In an analogous manner l-cyanogen-Q-suL- f0cyanogen-t-ethoxy-benzene yields 4;-ethoXy-benZene-1-carb0Xy-amido 2 merc'aptafi melting at about 285.

'Weclaim:

1. A process for manufacturing arylortho-carboXyamido-mercaptans which comprises treating an ortho-cyanogen-aryl-sulfocyanogen-compound of the general for- 2 mula:

ONO) scm2 With an acidic hydrolyzing agent. 2. A process for manufacturing arylortho-carboxyamido-mercaptans which comprises treating an ortho-cyanogen-aryl-sulfocyanogen-compound of the general formula: ON(1) 7 s ON(2) first with an acidic hydrolyzing agent, thereafter with an alkaline saponifying agent.

40 8. A process for manufacturing arylortho-carboxyamido-mercaptans which comprises treating an ortho-cyanogen-aryl-sulfocyanogen-compound of the general formula:

I CN(1) first with an acidic hydrolyzing agent, thereafter with an alkaline saponifying agent in the presence of a reducing agent.

4. A process for manufacturing arylortho-carboxyamido-mercaptans which comprises treating 1-n1ethyl-2'-cyanogen-3-sulfocyanogen-5-chlorobenzene first with an acidic hydrolyzing agent, thereafter with an alkaline saponifying agent in the presence of a reducing agent.

In testimony whereof, we aifi'x our signatures.

' RICHARD HERZl MAX SCHUBERT.- 

